Circularly Polarized Molecular High Harmonic Generation Using a Bicircular Laser

We investigate the process of circularly polarized high harmonic generation in molecules using a bicircular laser field. In this context, we show that molecules offer a very robust framework for the production of circularly polarized harmonics, provided their symmetry is compatible with that of the laser field. Using a discrete time-dependent symmetry analysis, we show how all the features (harmonic order and polarization) of spectra can be explained and predicted. The symmetry analysis is generic and can easily be applied to other target and/or field configurations

Cost effect of surgeon and patient discretion in regard to cataract surgery

Purpose: The purpose of this study is to examine the cost effect of surgeon and patient discretion in regard to cataract surgery and how this affects population health care costs. Methods: A model of cataract progression was created from preexisting published data and combined with mortality data and Medicare cataract statistics to estimate the effect of mortality on decreasing the rate of cataract surgery if surgery was delayed until any cataract progression occurred. Results: Five-year cataract progression rates were determined for a given patient age, sex, and type of cataract. Combined with 5-year death rates, delaying surgery until progression occurred resulted in a 1.1% decrease in surgery for nuclear sclerosis at age 45 that increased to a 33.8% decrease by age 90; a 1.5% decrease in surgery for cortical cataract at age 45 that increased to a 51.1% decrease by age 90; and a 1.6% decrease in surgery for posterior subcapsular at age 45 that increased to a 59.7% decrease by age 90. The effect of this decrease in surgical volume on Medicare was estimated to result in a 13% overall decrease in cataract surgery annually at a cost of ~$660 million dollars per year. Conclusion: Overall, we conclude that surgeon and patient discretion in regard to cataract surgery has a substantial cost effect with the potential to reduce surgical volume by as much as 13% by the decision to delay surgery as a result of patient mortality

Size Distribution of Superparamagnetic Particles Determined by Magnetic Sedimentation

We report on the use of magnetic sedimentation as a means to determine the size distribution of dispersed magnetic particles. The particles investigated here are i) single anionic and cationic nanoparticles of diameter D = 7 nm and ii) nanoparticle clusters resulting from electrostatic complexation with polyelectrolytes and polyelectrolyte-neutral copolymers. A theoretical expression of the sedimentation concentration profiles at the steady state is proposed and it is found to describe accurately the experimental data. When compared to dynamic light scattering, vibrating sample magnetometry and cryogenic transmission electron microscopy, magnetic sedimentation exhibits a unique property : it provides the core size and core size distribution of nanoparticle aggregates.Comment: 9 pages - templated ACS - 7 figures - 1 tabl

The Italian air force sea level pressure data set (1951-2000)

A set of 39 homogenised sea level pressure records, extracted from the Italian Air Force dataset (1951-2000), is introduced and analysed for trends. The data consist of 3-hourly observations. Daily mean pressures are obtained using a method that allows biases to be avoided due to the presence of a high fraction of days that do not have all 8 observations. Trend analysis is performed on seasonal and yearly basis and concerns both the individual station records and the series of their averages. The results show a highly significant positive trend in winter and yearly air pressure all over Italy. It is mainly due to a change-point around 1980. The Italian air pressure records are also compared with the NCAR/NCEP and UKMO gridded data sets. The results give evidence that gridded data capture most of the trend and variability of air pressure over Italy, even if NCAR/NCEP data display some significant inhomogeneities with respect to the station records